Mars24 Sunclock — Time on Mars
Credits, Acknowledgments and References
Mars24 was developed at the NASA Goddard Institute for Space Studies by Dr. Robert B. Schmunk based on algorithms derived by Dr. Michael D. Allison.
We thank members of the Mars Climate Orbiter and Mars Exploration Rover projects at NASA's Jet Propulsion Laboratory (JPL) for their assistance and encouragement in the development of Mars solar timing algorithms and the Mars24 sunclock.
We thank members of the Mars Phoenix project at NASA/JPL and the University of Arizona and members of the MSL Curiosity project at NASA/JPL and the Johns Hopkins University for their assistance in updates to Mars24 related to those projects' timekeeping.
We thank B. Semenov at NASA/JPL for his assistance in updates related to Mars InSight and Mars 2020 Perseverance project timekeeping.
Java Software Code Libraries
Mars24 uses several third-party, open-source Java libraries, provided under various licenses as listed. You may obtain the source code for these libraries at the URLs provided.
The Mars24 is primarily based on algorithms published in:
- Allison, M. 1997: Accurate analytic representations of solar time and seasons on Mars with applications to the Pathfinder/Surveyor missions. Geophys. Res. Lett., 24, 1967-1970, doi:10.1029/97GL01950.
- Allison, M., and M. McEwen 2000: A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies. Planet. Space Sci., 48, 215-235, doi:10.1016/S0032-0633(99)00092-6
Updates and adjustments post-2004 have been made based on:
- Allison, M., and J. Ferrier: Planetocentric solar coordinates, including efficient recipes for seasonal/diurnal timing on Saturn and Titan. Unpublished manuscript.
- Kuchynka, P., et al., 2014: New constraints on Mars rotation determined from radiometric tracking of the Opportunity Mars Exploration Rover. Icarus, 229, 340-347, doi:10.1016/j.icarus.2013.11.015.
- Seidelmann, P.K., et al., 2002: Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites: 2000. Celest. Mech. Dynam. Astron., 82, 83-110, doi:10.1023/A:1013939327465. (Also cf., Corrigendum, 2002. Celest. Mech. Dynam. Astron., 84, 429, doi:10.1023/A:1021101631766.)
Other works useful in the development of the Mars timekeeping algorithm and the Mars24 software, including landing site data and mission clocks, include:
- Colburn, D.S., et al., 1989: Diurnal variations in optical depth at Mars. Icarus, 79, 159-189, doi:10.1016/0019-1035(89)90114-0.
- De Vaucouleurs, G., et al., 1973: Mariner 9 areographic coordinate system. J. Geophys. Res., 78, 4395-4404, doi:10.1029/JB078i020p04395.
- Duxbury, T., et al., 2001: Mars Geodesy/Cartography Working Group recommendations on Mars cartographic constants and coordinate systems. International Society for Photogrammetry and Remote Sensing (ISPRS) Working Group Meeting IV/9.
- Ezell, E.C., and L.N. Ezell, 1984: On Mars: Exploration of the Red Planet 1958-1978, NASA SP-4212. National Aeronautics and Space Administration. (See esp. Ch. 10, "Site certification and landing.)
- Folkner, W.M., et al., 1997: Interior structure and seasonal mass redistribution of Mars from radio tracking of Mars Pathfinder. Science, 278, 1749-1751, doi:10.1126/science.278.5344.1749.
- Li, R., et al., 2005: Initial results of rover localization and topographic mapping for the 2003 Mars Exploration Rover mission, Photogramm. Eng. Remote Sens., 71, no. 10, 1129-1142, doi:10.14358/PERS.71.10.1129.
- Liu, J., et al., 2022: Geomorphic contexts and science focus of the Zhurong landing site on Mars. Nat. Astron., 6, 65–71, doi:10.1038/s41550-021-01519-5.
- Roncoli, R., et al., 2002: Mars Exploration Rover Project planetary constants and models - Version 2. Interoffice Memorandum IOM 312.F-02-003. NASA Jet Propulsion Laboratory
- Simon, J.L., et al., 1994: Numerical expressions for precession formulae and mean elements for the Moon and planets. Astron. Astrophys., 282, 663-683.
- Vaughan, R., 1995: Mars Pathfinder Project: Planetary Constants and Mode, JPL D-12947. NASA Jet Propulsion Laboratory.
- Vaughan, R., 1997: MPF Lander Mars Local Times. Webpage at mars.nasa.gov/MPF/mpf/mpftechtraj.html#MDATA (last accessed 2020-01-05).
Mission clock information for NASA's Mars Phoenix was provided by M. Garcia (2007-09) and K. Fujii (2008-05).
Mission clock information for NASA's MSL Curiosity was provided by S. Krasner (2012-02) and B. Semenov (2012-07).
Mission clock information for NASA's InSight was provided by B. Semenov (2018-02, 2018-11, 2019-04).
Mission clock information for NASA's Mars 2020 Perseverance was taken from a NASA/JPL/NAIF/SPICE document by Acton & Semenov dated August 2020.
Sunclock Map Images
The "MOC_MOLA_NGS_Map" sample map is derived from an image created by Malin Space Science Systems by combining Mars Global Surveyor (MGS), Mars Orbiter Camera (MOC), and Mars Orbiter Laser Altimeter (MOLA) data for a map to be used by the National Geographic Society. The base image was obtained from the MOLA Science website and re-projected.
The "MOC_MOLA_Color_Relief" sample map was created by the MGS MOLA team and was also obtained from the MOLA Science website.
The "VIS_MDIM_1_Map" sample map was obtained from the USGS Astrogeology Research Program "Map-a-Planet" PDS Imaging Node and is a combination of Viking project Visual Image Subsystem (VIS) color imagery with Viking Mars Digital Image Model Version 1 (MDIM1) data.
The "VIS_MDIM_2.1_Map" sample map was obtained from the USGS Astrogeology Science Center and is a combination of Viking project Visual Image Subsystem (VIS) color imagery with Viking Mars Digital Image Model Version 2.1 (MDIM2.1) data.
Landing Site Panorama Images
The local panorama images at three lander sites are derived from panorama images released by the lander projects.
The Phoenix panorama combines two images, the black and white image PIA10733 released May 29, 2008, and color image PIA11007 released July 31, 2008. The Phoenix images are courtesy NASA/JPL-Caltech/University of Arizona/Texas A&M University.